No class today.  Hope your rehearsal went well.  Unit test tomorrow.
 
Buffers help acid-base equilibrium systems to resist changes in pH.  There is extra help on Monday.  The test is on Tuesday.
Homework:  Read p.615-620 and answer p.620 Practice #1, 2; Section #2-4
 
Indicators play an important role in titrations.  The choice of a good indicator depends on whether you use strong or weak acids or bases to react, and therefore, on whether the salt produced causes hydrolysis.  Text reference is p.595-613.
Your unit test for acid-base equilibrium is on Tuesday, June 1, 2010.
Homework:  State the difference between "endpoint" and "equivalence".  Answer p.599 #1, 2; p.613 #10, 1, 2, 5; p.614 #10
Review for test: p.636 #2, 11, 13-15, 17-30, 32-39; p.641 #27-29, 32, 33, 38, 40, 42, 46, 48, 51
 
Some salt solutions are neutral, but some are acidic and some are basic.  Consult your text p.581-587 for the reason, and some examples.  Unit 4 Test, Part 2 is next Tuesday, June 1.
Homework:  p.579 #11, 16; p.588 #1, 2; p.594 #2, 4, 5
 
Read p.574 about Ka of polyprotic acids.  Kb is similar to Ka, but is for weak bases.  Consult p.570-573.  Some weak bases do not have their Kb values listed in the table in the back of the text.  To calculate these, see p.570.
Homework:  p.579 #9, 15; p.574 #13
 
Weak acids only partially ionize, setting up an equilibrium between the whole acid molecule and the ions it makes.  From this, we get an equilibrium constant for acids.  Consult the text, p.542-551, 563-568.
Homework:  p.546 #12-14; p.549 #18; p.568 #7, 8
 
We reviewed acid-base theories, terminology, and pH, and learned about Kw, the ionization constant for water.  Text reference is p.528-541.  The outline of the lesson is on the Unit 4 page of the website. 
Homework:  p.532 #1-3; p.537 #4, 5; p.540 #8, 10
 
Test day.  Complete the Ksp lab reports and hand them in.  If you have not done the experiment, come at lunch tomorrow (Thursday) and complete it.
 
Prepare for your test tomorrow.  Review questions are on the 05/13/2010 homework posting.  Don't forget to complete your lab report for the Ksp lab - they were due today.  If you were absent for the lab, the makeup date is Thursday, May 20 at lunch.
 
If you try to dissolve some calcium carbonate into a solution of sodium carbonate, even less than usual will dissolve, because there is already carbonate ion present.  This shifts the dissociation equilibrium of calcium carbonate towards the solid so less dissolves.  Refer to text p.490-492.
Homework:  p.492 #8, 9, 11, 12